[1] [1] Y. Ma, X. Wang, Y. Jia, X. Chen, H. Han and C. Li, Chem. Rev. 114, 9987 (2014).

[2] [2] H.B. Wu, H.H. Hng and X.W. Lou, Adv. Mater. 24, 2567 (2012).

[3] [3] B. O’Regan and M. Gr ztel, Nature 353, 737 (1991).

[4] [4] S. Mathew, A. Yella, P. Gao, R. Humphry-Baker, B. F. E. Curchod, N. Ashari- Astani, I. Tavernelli, U. Rothlisberger, Md. K. Nazeeruddin and M. Gr tzel, Nat. Chem. 6, 242 (2014).

[5] [5] H. Tong, S. Ouyang, Y. Bi, N. Umezawa, M. Oshikiri and J. Ye, Adv. Mater. 24, 229 (2012).

[6] [6] C. Du, X. Yang, M.T. Mayer, H. Hoyt, J. Xie, G. McMahon, G. Bischoping and D. Wang, Angew. Chem. Int. Ed. 52, 12692 (2013).

[7] [7] W.J. Jo, J.W. Jang, K. Kong, H.J. Kang, J.Y. Kim, H. Jun, K.P.S. Parmar and J.S. Lee, Angew. Chem. Int. Ed. 51, 3147 (2012).

[8] [8] Z. Zou, J. Ye, K. Sayama and H. Arakawa, Nature 414, 625 (2001).

[9] [9] B. Liu and E.S. Aydil, J. Am. Chem. Soc. 131, 3985 (2009).

[10] [10] X.Q. Gu, Y.L. Zhao and Y.H. Qiang, J. Mater. Sci. Mat. Electron. 23, 1373 (2012).

[11] [11] H. Wang, Y. Bai, H. Zhang, Z. Zhang, J. Li and L. Guo, J. Phys. Chem. C 114, 16451 (2010).

[12] [12] C. Wang, Z. Chen, H. Jin, C. Cao, J. Li and Z. Mi, J. Mater. Chem. A 2, 17820 (2014).

[13] [13] X. Wang, J. Xie and C. M. Li, J. Mater. Chem. A 3, 1235 (2015).

[14] [14] J. Su, L. Guo, N. Bao and C.A. Grimes, Nano Lett. 11, 1928 (2011).

[15] [15] H. P. Maruska and A. K. Ghosh, Sol. Energy 20, 443 (1978).